The present invention relates to a cycle that is adapted to evolve between a tricycle configuration and a bicycle configuration, and to a corresponding bicycle and tricycle.
Tricycles exist for use by children from the age of two onwards. For older children, bicycles, optionally fitted with stabilizing side wheels also exist. Each of these, in itself, is satisfactory.
European Patent Application 0,187,170 discloses a bicycle having a rear wheel carrier in the form of a beam, into which a chain transmission is built. In this bicycle, like the bicycle disclosed in French patent application 2,611,641 the rear wheel is mounted in cantilevered fashion on the bicycle frame.
The invention provides a solution to the new problem of adaptability of cycles, notably cycles for use by children. As the psychomotor capacities of children develop, parents who purchased a tricycle are obliged to then fairly quickly purchase a bicycle fitted with removable stabilizing sidewheels. Apart from the problem of cost, a learning problem arises; both problems are resolved by this invention.
Cycles are already known which can be transformed from a bicycle into a tricycle. Thus, German patent 28,381 (1883) discloses the transformation of a cycle from a bicycle into a tricycle, and vice-versa. The solution disclosed in that document is however not satisfactory as it involves carrying out extremely complex technical modifications, as, according to this document, it is necessary to replace the complete rear-end system; indeed, the axle carrying the rear wheels is completely removed, in order to be replaced by a single axle carrying the rear wheel when the cycle changes from a "tricycle" configuration to the "bicycle" configuration.
U.S. Pat. No. 3,532,351 (1970) discloses a cycle that can be transformed from a cycle into a tricycle, with, in the tricycle position, only one single driving wheel. Transformation is achieved by rotating a rear auxiliary chassis, this rear chassis carrying the two tricycle wheels, one axle carrying a wheel being engaged into the drive mechanism at the rear. Not only is this solution technically complex, but, additionally necessitates significant skill and availability of tools.
All these prior art documents disclose complex technical solutions which require heavy use of tools and which are difficult to carry out by the child's parents. The invention provides a simple solution which only requires limited use of tools, or even no tools at all, and which is easy to carry out.